Such an electric lamp is known from U.S. Pat. No. 3,262,001. In the known lamp, the two brackets of the retaining member are fixed to each other by means of soldered or welded joints. The retaining member has thereby been coupled to the lamp vessel before it is inserted in the lamp cap. The brackets are bent alongside the shell of the lamp cap in mutually opposing directions.
A disadvantage of the known lamp is that only a narrow spread is allowable as to the thickness of the pinched seal of the lamp vessel, otherwise the retaining member will have no or no secure coupling with the lamp cap, or will cause excessive strain in the pinched seal.
Another disadvantage is that the retaining member, before it is inserted in the lamp cap, has to be compressed in order to assume dimensions which are smaller than the dimensions which it is to have at a later stage to effect all-round contact with the lamp cap. This involves the risk of the retaining member, when applied in the lamp cap, springing back to a degree which is insufficient for effecting fixing points to the lamp cap.